<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
   <style>
    .one{
        height: 500px;
        width: 400px;
        background-color: green;
        margin: 0 auto;
    }
    .two{
        height: 500px;
        width:  200px;
        background-color: red;
        float: left;
    }
    .three{
        height: 500px;
        width: 200px;
        background-color: skyblue;
        float: right;
    }
    .container{
        height: 100px;
        width: 400px;
        background-color: blue;
        margin: 0 auto;
    }
   </style>
</head>

<body>
    <div class="container"></div>
    <div class="one">
        <div class="two"></div>
        <div class="three"></div>
    </div>

</body>

</html>